package org.example.record;

import java.util.Optional;

public record Student(Integer id, String name, String email, int age) {

    // 实例方法，concat连接字符串
    public String concat() {
        return String.format("姓名是%s, 年龄是%d", this.name, this.age);
    }

    // 静态方法，把email转为大写
    public static String emailToUpperCase(String email) {
        return Optional.ofNullable(email).orElse("no email").toUpperCase();
    }

    // 紧凑
    public Student {
        System.out.println("id=" + id);

        if (id < 1) {
            throw new IllegalArgumentException("id is less than 1");
        }
    }

    // 定制构造方法
    public Student(Integer id, String name) {
        this(id, name, null, 0);
    }
}
